HLA-A*26 has been linked to acute Graft-versus-host disease (GVHD) after allogeneic stem cell transplantation [17], to lymphoproliferative disorders after solid organ grafts [18], as well as to specific forms of psoriatic arthritis [19] as a sign for a pathogenetic role also in other clinical diseases. The gene discussed is HLA-A; the disease is lymphoproliferative syndrome.